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Rocky Mountain National Park · Colorado

Wild Basin: Thunder Lake, Lion Lakes, and Upper Ouzel

A difficult two-night Wild Basin lollipop that camps at Thunder Lake, visits Lion Lake No. 1 on the maintained trail network, then camps at Upper Ouzel Creek before returning to the same trailhead. Lion Lakes is a route destination—not a permit campsite in this watch.

Wild Basin Trailhead to Wild Basin Trailhead via Thunder Lake, Lion Lake No. 1, and Upper Ouzel Creek

The lollipop. The shape of it

Three high basins make one sustained Wild Basin lollipop.

Elevation profile of the approximately 22.5-mile Wild Basin route from Wild Basin Trailhead to Thunder Lake, Lion Lake Number 1, Upper Ouzel Creek, and back, with Thunder Lake and Upper Ouzel Creek permit-night markers Night 1 permit location at mile 6.206 Night 2 permit location at mile 16.732
The complete route stitches the current COTREX Thunder Lake, Lion Lake No. 1, and Bluebird Lake featured-route geometry at exact shared coordinates. Upper Ouzel ends at the route sample nearest the current designated-site coordinate. Permit squares mark representative trail points near the designated sites, not tent coordinates or site boundaries.
  1. Middle destination · mile 10.162

    Lion Lake No. 1 ≈11,075 ft Lion Lake No. 1 is the route destination between the two reserved campsite nights; it is not a permit offer in this watch.
  1. Wild Basin Trailhead Exact catalog entry
  2. Thunder Lake Night 1 · individual site
  3. Lion Lake No. 1 Middle route destination · no permit night
  4. Upper Ouzel Creek Night 2 · individual site
  5. Wild Basin Trailhead Exact catalog exit
Route length
≈22.5 miles
Total climbing
≈6,180 ft gain
High point
≈11,115 ft
permit option
Individual sites · 1–7 people
This itinerary
2 nights / 3 trail days

Start and finish at Wild Basin Trailhead. Reach Thunder Lake for Night 1, backtrack to the Lion Lake junction and visit Lion Lake No. 1, then return through the shared trail network to Upper Ouzel Creek for Night 2 before hiking out.

Follow the Wild Basin trail network to the Thunder Lake individual campsite for Night 1. The National Park Service lists three individual sites in the forest west of the trail, at 10,570 feet, with a privy and treatable water at the lake inlet and outlet streams.

On the middle day, backtrack to the Lion Lake junction, climb the maintained Lion Lake Trail to Lion Lake No. 1, then reverse to the shared junction and continue toward Bluebird Lake. Camp at Upper Ouzel Creek for Night 2; the designated site is about 0.7 mile below Bluebird Lake.

Return to Wild Basin Trailhead on the third trail day. The complete geometry contains deliberate retraced sections between the three branches; it is a lollipop assembled from the exact published trail paths, not a cross-country shortcut.

Night by night

Two reserved nights around one Lion Lakes visit

Thunder Lake is Night 1. Lion Lake No. 1 is the middle trail destination, not a permit night. Upper Ouzel Creek is Night 2.

  1. N1

    Thunder Lake

    Individual wilderness campsite · advance reservation

    Climb from Wild Basin Trailhead through the North St. Vrain corridor to the fixed first-night campsite near Thunder Lake.

    Thunder Lake · Designated individual wilderness campsite · advance reservation

    • Thunder Lake (Snow-free average: July 5)

    Reserve the active Thunder Lake individual-site offer for Night 1. The separate group, stock, winter, and cabin offers do not substitute.

    Over
    Thunder Lake Trail
    Camp elevation
    10,570 ft site listing
    Water
    Treat inlet or outlet water

    On the ground. The National Park Service lists three individual sites and a privy. Group, stock, and cabin inventory are separate inventory types.

  2. N2

    Upper Ouzel Creek

    Individual wilderness campsite · advance reservation

    Visit Lion Lake No. 1, return to the shared junction, and follow the Bluebird Lake corridor to the fixed second-night site.

    Upper Ouzel Creek · Designated individual wilderness campsite · advance reservation

    • Upper Ouzel Creek (Snow-free average: July 6)

    Reserve the active Upper Ouzel Creek individual-site offer for Night 2. Ouzel Lake and winter Ouzel Creek are different provider locations.

    Over
    Lion Lake No. 1
    Camp elevation
    10,600 ft site listing
    Water
    Treat creek water

    On the ground. The National Park Service lists one site and no privy, about 0.7 mile below Bluebird Lake.

The permit

How this two-site Wild Basin watch works

The watch requires both named individual-site offers on consecutive trip dates. It reports openings; it never books, buys, or holds a permit.

Two exact site-dates
Thunder Lake must be available for Night 1 and Upper Ouzel Creek for Night 2. One opening alone does not complete the itinerary.
Lion Lakes is not inventory
Lion Lake No. 1 is visited on the middle trail day. Recreation.gov does not list Lion Lakes as a campsite offer for this permit.
Parties one through seven
This trip uses only current individual-site offers whose provider rules support parties of one through seven.
Annual opening
Current guidance opens advance reservations for the May-through-October camping season on March 1 at 8:00 a.m. Mountain Time.
Pickup and access
The permit must be picked up in person. Current guidance says it also serves as timed entry for the permit duration; park entrance requirements remain separate.
Returned inventory
A canceled reservation may make its sites available again, but the authority gives no guaranteed return minute.
An alert is not a booking
Wild Chime only reports qualifying inventory. The traveler must complete Recreation.gov checkout and every park requirement.

Primary planning intent

Wild Basin campsite-order answers.

Lion Lakes is a route visit between two reserved camps, not a third overnight in this watch.

Do I reserve Lion Lakes?

No. This itinerary visits Lion Lake No. 1 on the maintained trail network between the two camps; it is not an overnight selection in this watch.

Thunder Lake Wilderness Campsite

Hard-won

Nine things worth knowing first

The branch order, campsite identities, long middle day, and live Wild Basin checks worth settling before departure.

Shape

Expect deliberate backtracking

The safe published route retraces shared trail between the Thunder, Lion, and Upper Ouzel branches; it does not cut cross-country between lakes.

Night 1

Thunder is exact

Choose the individual Thunder Lake offer—not its group, stock, winter, or cabin offers.

Middle day

Lion is the long link

The measured profile places about 10.5 route miles between the two permit markers, including the Lion Lake No. 1 visit.

Night 2

Upper Ouzel is exact

Upper Ouzel Creek is separate from Ouzel Lake and winter Ouzel Creek inventory.

Profile

The climbing repeats

Three high branches create roughly 6,180 feet of cumulative climbing even though the route never reaches a named pass.

Weather

No start time guarantees safety

Use current forecasts and observations, and make conservative decisions as mountain conditions change.

Food

Bring the required canister

Current permit guidance requires a hard-sided bear-resistant food-storage canister and in-person inspection at pickup.

Fire

Plan on current stove rules

Campfires are prohibited at both wilderness sites; recheck temporary fire restrictions before leaving.

Before leaving

Recheck every live authority

Wild Chime does not monitor trails, snow, water, weather, closures, fire restrictions, parking, or transportation.

Questions

Wild Basin: Thunder, Lion & Upper Ouzel, asked and answered

Which direction does this exact trip use?

It starts at Wild Basin Trailhead, camps at Thunder Lake, visits Lion Lake No. 1, camps at Upper Ouzel Creek, and returns to Wild Basin Trailhead.

Do I reserve a Lion Lakes campsite?

No. Lion Lake No. 1 is a trail destination on the middle day. The two reserved nights are Thunder Lake and Upper Ouzel Creek.

Can similarly named offers substitute?

No. Group, stock, winter, cabin, and Ouzel Lake offers are different provider locations and do not satisfy these fixed legs.

How hard is the middle day?

The measured route places about 10.5 miles between the two permit markers, with a climb to Lion Lake No. 1 and another climb toward Upper Ouzel.

Does the wilderness permit include timed entry?

Current Recreation.gov guidance says the wilderness permit serves as timed entry for its duration, but entrance fees and all other requirements still apply.

Does an alert reserve the permit?

No. An alert only reports qualifying openings. Wild Chime never books, buys, holds, or completes checkout.

Keep the intent distinct

More trips in Rocky Mountain National Park.

Compare exact permit-night orders rather than substituting a nearby route or reversing the dates.

Exact-trip availability

Watch Wild Basin: Thunder Lake, Lion Lakes, and Upper Ouzel.

Start with this exact direction, overnight order, and the permit locations that fit the saved party. Wild Chime reports qualifying openings; it never books or holds them.

Create this trip’s watch

For this exact direction and two-night permit order.

Review the current permit on Recreation.gov